四分律刪繁補闕行事鈔 1.398

1.398

父母聽不者。《善見》云：若餘方國度者，不須問。《僧祇》：親兒此彼不聽；自來兒、養兒，餘處得受。

Regarding whether parents consent: The Samantapāsādikā says: If one ordains someone from another country, one need not ask. The Mahāsāṃghika-vinaya says: One's own biological son is not permitted either here or there; a son who comes on his own, or an adopted son, may receive [the precepts] elsewhere.